What is a Surform?
A Surform is a hand tool with a thin steel blade full of punched holes, each rim sharpened into a tiny cutting edge. The blade fits in a holder shaped like a plane, a file or a rasp. Each hole cuts a small shaving that passes through the opening to the back. That is why the blade rarely clogs, unlike an ordinary rasp.
Surform is a trade name. The blade was developed in Britain around 1949 and sold by Stanley from 1956; Stanley later bought the company. Many people now use “Surform” as a generic name, alongside rasp-plane or shaper. Blades come in fine and coarse cuts and in flat, half-round and round versions.
In practice
- Trim plasterboard. A few strokes make a cut edge straight and clean so the board fits tightly.
- Rough-shape timber. Round over edges, ease a door that sticks at the bottom, or fit a board. Finish afterwards with sandpaper or a plane.
- Insulation and soft materials. Rigid foam (EPS, PIR), cork, plastics and soft metals such as aluminium and lead shape well.
- Work in the right direction. The blade cuts on the push stroke. Work diagonally across the piece for a flatter result and keep the pressure even.
- Replace the blade in time. A dull blade tears rather than cuts. Replacement blades are cheap and quick to change.
Common mistake: expecting a smooth finish from a Surform. It always leaves scratches; you need a plane or sandpaper to finish. It is not suitable for hardened steel or stone.
Related terms
- Wood rasp
- Block plane
- Jointer plane
- Router plane
- Planer
Want to know more about building terms? Visit our knowledge base at fredsdiyplans.com.